Method of producing laminated products



E. H. MERRITT METHOD OF PRODUCING LAMINATED PRODUCTS Filed March 8, 19322 Sheets-Sheet 1 INVENTOR 2/ ATTO RaEY Oct. 30, 1934. E. H. MERRITTMETHOD OF PRODUCING LAMINATED PRODUCTS Filed Mafch 8, 1952 2Sheets-Sheet 2 |NVENT?/RV BYW W gATTORNEY -fl m l r MN 3 Q Patented Oct.30, 1934 PATENT OFFICE METHOD OF PRODUCING LAMINATED PRODUCTS EricssonH. Merritt, Loekport, N. Y., assignor to Laminating Patents Corporation,

Seattle,

Wasln, a corporation 01' Delaware Application March 8, 1932, Serial No.597,448

This invention relates to faced mineral board and methods of forming thesame, and in its 'more specific aspects to mineral boards faced withveneer, and to methods for bonding veneer and mineral board.

Among the objects of the invention is the pr ovision of an improvedproduct which coinbines fire-resistant qualities with stre gtdurability, and appearance, and the provision of particularly effectivemethods for the formation of such a product.

A further object is to provide a wood faced product having improvedfire-resistant properties and presenting an attractive appearance.

Another object is the provision of an improved method for uniting veneerand mineral board.

Other. objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the several steps and the relationand order of one or more of suchsteps with respect to each of theothers, and the article possessing the features, properties; and therelation of elements, which are exemplified in the following detaileddisclosure, and the scope of the application of which will be indicatedin the claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawings, in

which: r

Figure 1 is a perspective view of an article embodying the invention; 1

Fig. 2 is an enlarged-fragmentary view of a faced mineral board;

Fig. 3 is a similar view of a faced mineral board having a surfacecoating;

Fig. 4 is a diagrammatic showing of the mode of procedure embodying theinvention;

. Fig. 5 is a diagrammatic showingof another mode of procedure embodyingthe invention; and

Fig. 6 is a diagrammatic showing of a further modification.

Various types of mineral boards are available for structural and-otherpurposes, and many of wall board comprising mineral board and a facingmaterial, which may desirably be veneer, (which term is utilized hereinto describe wooden sheet material) united thereto. It has been foundthat a synthetic resinous material such, for example, as aphenol-formaldehyde condensation product and similar phenoliccondensation products, provides a particularly effective bond yielding aproduct having especially desirable qualities for insulating and otherproperties.

A product embodying the invention is illustrated in Fig. 1. Thiscomprises a mineral board base 8 which may desirably be a dense,substantially incompressible board formed from a composition, theprincipal ingredients of which are asbestos and Portland cement. Unitedto the mineral board by a suitable synthetic resinous adhesive(indicated at 9 in Fig.2), which may desirably be a phenoliccondensation product, is a facing 10 of veneer.

This product possesses the fire-resistant properties, sturdiness andstifiness of the mineral board and at the same time presents anexceedingly attractive appearance for use in panels, .walls, trim andother places wherein such com bined qualities are desirable. Thesynthetic resinous binder adds to, rather than detracts from, thefire-proofing and water-proofing qualities of the product.

If desired, the exposed surface of the facing material may be coatedwith a phenolic condensation product or other synthetic resinousmaterial, such a coating being indicated at 11 in 'Fig. 3.

As above noted, various types of mineral board. may be utilized. Amongthese are cement-asbestos boards as mentioned above, gypsum-containingboards, boards composed principally of cement, and many others.

In certain instances, a product comprising mineral board and a facing ofpaper or textile material united thereto by means of a syntheticresinous adhesive may be provided.

A variety of difliculties are encountered in the uniting of veneer andother facing material to mineral board. Among these are the difllcultiesin uniting veneer to an incompressible layer having an uneven surface,the tendency toward the formation of bmters due to excessive moisturecontained in the mineral board or applied thereto, and difficulties inobtaining a strong bond and in providing a good appearance. Certainfeatures of the invention relate-to the provi ion of a method foruniting such members no whereby the foregoing and other difficulties maybe overcome.

By way of example, certain types of procedures are described below.

In the form of procedure illustrated diagrammatically, in Fig. 4 slabs12 of a dense, substantially incompressible mineral board which may beformed from a composition, the principal ingredients of which areasbestos and Portland cement, are subjected to a smoothing treatment, asfor example, in a grinding machine 13, whereby unevenness in one of thesurfaces thereof is eliminated. The slabs are thereupon heated to reducethe moisture content, preferably to a point wherein each section will.contain less than 6% moisture- Sections of pre-cut veneer 14 arepreferably dried to a pointwhere they contain less than about 6% to 8%moisture by weight. Desirably, sections of both materials may be driedin a veneer drier 15 such, for example, as that'illustrated in thepatent to Louis G. Merritt, et al.-No. 1,757,092. Each section ofmineral board coming from the drier is passed by a conveyor 16 under adisseminating mechanism 17 whereby an incomplete, potential.- lyreactive, phenolic condensation product is applied to' the smoothsurfacethereof inpowdered form. The applying mechanism may desirably beof a type illustrated in the co-pending application of Louis G. Merrittand Ericsson H. Merritt, Serial No. 542,257, filed June 5, 1931. In thepresent instance the sections are passed under the disseminatingmechanism while they still contain a considerable amount of heat, asurface temperature of from 200 to 250 F. being desirable.

The amount of resin applied may desirably run from 8 to 17 pounds perthousand square feet of surface-spread.

The heat tends to cause a certain amount of melting of the resinousparticles which tends to cause them to adhere firmly to the surface andto prevent displacement of particles as setforth in the co-pending'application of Ericsson H. Merritt, Serial No. 582,253, filed December21, 1931.

Sections of veneer coming from the drier are passed either manually orby suitable automatic means to a point beyond the disseminator 17 anddisposed against the coated surface of the mineral board sections toform an assembly. Then these assemblies are suitably subjected to heatand pressure as in a veneer press 19. The heat may desirably range from300 to 360 F.

and the pressurefrom to 500.pounds per square inch, and the bondingtreatment continue for from to"4 minutes. In certain instancesthepressed panels may be subjected while still hot to a pressure ofone-half a pound per square inch and be so held until cooled.

In the event that a coating on the veneer surfaceis desired, this may bedesirably formed by providing a layer of potentially reactive syntheticresinous material, such as a phenolic condensation product in powderedform, upon the exposed surface of the veneer either by passing theassemblies under a further disseminating mechanism, by passing theveneer sheets on a parallel conveyor under a'further disseminatingmechanism, by running mineral board sheets and veneer sheets alternatelyunder the disseminating mechanism 17 if the same resinous material is tobe used, or in any other suitable manner, after which the assemblieswill be subjected to bonding conditions.

which, as adapted to the present invention, is

illustrated diagrammatically in Fig. 5"and described below. I

Sheets of mineral board 20 are run on a conveyor 21 under a sprayingmechanism 22, whereby there is applied thereto an aqueous solutioncontaining phenol, acaustic alkali, and ammoniav in suitable proportion,such as 56 parts of phenol, 18 parts of 20% caustic soda solu-' tion,and 7 parts of 37% ammonia solution. This may be applied at the rate of3 pounds per 1,000 square feet of surface area. The mineral board sheetsare thereupon run under a spreading mechanism 23, whereby 13 pounds ofpowdered phenolic condensation product per 1,000 square feet of surfacearea is applied thereto, and thence under a second spraying mechanism24, whereby 3 pounds of furfural per 1,000 square feet, of surface areais applied. A sheet of veneer 25 is laid upon the coated surface of themineral board, and the assembly subjected to heat and pressure in a hotpress 26.

Another desirable type of procedure is by spreading liquids and resin,in the manner exemplified immediately above, on veneer sheets 27, anddisposing thereagainst a mineral board layer 28 which has been heated toabout 250 F. to 300 F., as by a heatingmeans 29, and subjecting theassembly to heat and pressure in a foo hot plate press 30 without anysubstantial lapse of time. The heating of the mineral board immediatelybefore it is placed in the press eliminates delay in the transferof heatthrough this material, which is comparatively diflicult for the heat topenetrate, and serves to provide a proper temperature at the gluelinesubstantially at the same time as the application of pressure.

It is to be understood that a number of variations in the manner ofapplying a'liquid or in the liquid applied, as indicated in theabovementioned application of Ericsson H. Merritt, Serial No. 597,447,filed herewith, or otherwise, may be made without departing from theinvention.

Many types of resinous materials may be uti-. lized in accordance withthe invention. 'Particular reference may be made to. phenoliccondensation products, to urea condensation and polymerization productsand to synthetic resinous materials containing vinyl acetate and/orvinyl chloride, which are thermo plastic but not thermo setting, i. e.,which set upon, cooling after the application of heat.

As an example of a particular type of phenolic condensation productwhich may desirably. be utilized, in some instances reference .may bemade to a resinous material produced in accordance with the followingprocedure:

Place 200 grams warm phenol in a metal container about 4" diameter by 5"high arranged 'for the attaching of a reflux, and add 20 grams of KOHdissolved in 20 cc. water, add while stirring .300 grams--37%formaldehyde solution. Attach reflux and apply heat until mass boilsfreely, then remove heat, as action is exothermic, for about 5 minutesor until ceases. Then again apply heat and boil with reflux for a totaltime of one hour and ten minutes, then remove reflux. The fluid, while ahot, will be rather viscous but still capable of being easily stirred.The fluid should now be stirred while still applying heat to evaporatefree water and phenol. When the mass becomes too stiff for stirring, itshould be removed from the container and cooled slowly. The total massof the resin will be approximately370 grams. After complete cooling themass is hard and brittle and can be broken up and ground to a powder. V

Since certain changes in carrying out the above process, and certainmodifications in the article which embody the invention may be madewithout departing from its scope, it is intended that all mattercontained in the above description or shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense. I

It is also to be understood-that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which as amatter of'language might be said to fall therebetween.

Having described my invention what I claim as new and desire to secureby'Letters Patent is:

1. The method of joining mineral board and veneer to form a laminatedproduct which comprises applying an adhesive material indiscreteparticle form to a surface of one of said members, associatingsaid surface with the surface of another of said members, and subjectingto bonding: conditions.

2. The method of facing mineral board which comprises associating asheet of facing material therewith with interposed potentially reactivesynthetic resinous adhesive in discrete-particle form, and subjecting toheat and pressure.

3. The method of joining mineral board and veneer to form a laminatedproduct, which comprises applying a potentially reactive syntheticresinous adhesive in powdered form to a surface of one of said members,associating said surface with the surface of the other of said members,and subjecting to bonding conditions.

4. The method of joining mineral board and veneer to form a laminatedproduct, which comprises applying a potentially reactive phenoliccondensation product in powdered form to a surface of one of saidmembers, associating said surface with the surface of the other of saidmembers, and subjecting to heat and pressure.

. comprises reducing the moisture content of each of. said members to apoint where its moisture content is less than 6 to 8% of its weight,applying a potentially reactive synthetic resinous adhesive in powderedform to a surface of one of said members, associating said surface withthe surface fthe other of said members, and subjecting to bondingconditions.\

'7. The method of joining mineral board and veneer to form a laminatedproduct, which "comprises smoothing the surface of a mineral board,associating therewith a veneer sheet with interposed potentiallyreactive synthetic resinous I I adhesive in discrete-particle form, andsubjecting to heat and pressure. I

8. The method of joining mineral board and veneer to form a laminatedproduct, which comprises applying a potentially reactive phenoliccondensation product in powdered form to the surface of the mineralboard, superposing a sheet of veneer, and subjecting to bondingconditions.

9. The method of joining mineral board and veneer to form a laminatedproduct, which comprises applying a potentially reactive phenoliccondensation product in powdered form to the surface of the veneer,superposing a sheet of mineral board, and subjecting tobondingconditions. C

10. The method of joining mineral board and veneer to form a laminatedproduct, which veneer to form a laminated product, which Y comprisescontinuously disseminating a liquid in a given zone, continuouslydisseminating a po tentially reactive synthetic resinous material inpowdered form in a' second zone, and continu ously disseminating aliquid in a third zone, passing mineral board sheets one after anotherthrough saidzones, associating a. veneer sheet with each mineral, boardsheet, and subjecting to heat and pressure.

12. The method of joining mineral board and veneer to form a laminatedproduct, which comprises applying a potentially reactive syntheticresinous material in discrete-particle form to the surface of a veneersheet, heating a mineral board sheet,- disposing the mineral board sheetupon said surface, and substantially immediately subjecting the assemblyto heat and pressure.

13. The method of joining mineral board and veneer to form a laminatedproduct, which comprises preheating one of said members, applying apotentially reactive synthetic resinous material in powdered form to asurface thereof, associating a surface of the other member with a coatedsurface, and subjecting to bonding thereof and to impart to the mineralboard.

sheet a surface temperature in the neighborhood of 200 to 250 F.,substantially immediately thereafter applying a potentially reactivephe- I nolic condensation product in powdered form to said sheet,superposing the veneer sheet, and subjecting to bonding conditions.

15. The method of forming laminated products, which comprises ,passingmineral board sheetsone after another and veneer sheets one afteranother through a heating and drying zone, passing each mineral boardsheet through a zone in which a powdered potentially reactive syntheticresinous material is disseminated, superposing a heated and dried veneersheet on each mineral board sheet and subjecting each of' the assembliesthus formed to bonding conditions.

16. The method of forming laminated products, which comprisesassociating a mineral board layer and a veneer layer with interposedpotentially reactive synthetic resinous material in discrete-particleform, a coating layer of potentially reactive synthetic resinousmaterial being provided. on the veneer sheet, and subjecting to bondingconditions.

1'7. The method of facing mineral board with wood veneer, whichcomprises applying to one of said members a potentially reactivesynthetic resinous material in powder form in the absence of suflicientmoisture to .liquefy the glue or to m'zalaov

